#单继承
class Amphibian:
    name = "两栖动物"
    def features(self):
        print("幼年用鳃呼吸")
        print("成年用肺兼皮肤呼吸")
class Frog(Amphibian):
    def attr(self):
        print("我会呱呱叫")

#创建Frog对象
frog = Frog()
print(frog.name)
frog.features()
frog.attr()


#多继承
class English:
    def receive_eng_know(self):
        print('具备英语知识。')
class Math:
    def receive_math_know(self):
        print('具备数学知识。')
class Student(English, Math):
    def study(self):
        print('学生的任务是学习。')

stu = Student()
stu.receive_eng_know()
stu.receive_math_know()
stu.study()
